5.1 - 5.5 AP Environmental Science Unit 5

tragedy of the commons

individuals will use resources in their own self-interest without sharing the common good, thereby depleting the resources

how to regulate use of resources

hunting/fishing licenses, land use permits, country quotas, selective cutting of trees

how to replenish resources after use

replant trees, throw back fish, rotate which grasslands are used for grazing

clearcutting

cutting down all the trees in a forest

impacts of clearcutting

soil erosion (loss of stabilizing root structure), increased soil & stream temp (loss of tree shade), flooding & landslides (compact soil from logging machinery)

the green revolution

shift in agriculture to industrial scale agribusinesses

mechanization

tractors for field work and compacts soil (topsoil more prone to erosion)

HVU crops

hybrid or genetically modified crops that produce higher yield overall

GMOS

crops that have genes for drought tolerance, pest resistance, faster growth, and diseases

synthetic fertilizer

highly concentrated, specific, increases yield with more key nutrients

pesticides

chemicals sprayed on crops that kill weeds, insects, rodents, etc

irrigation

distributes water from the ground or other surface waters on fields to increase plant growth

energy subsidy

fossil fuel/human energy input per calorie of food produced

monocropping

growing single species of crop (decreases biodiversity, increases erosion)

tilling

breaking or mixing up soil to make planting easier (lossens soil for roots, increases erosion)

slash & burn

cuts vegetation to clear land but results in deforestation and nutrients depleted

leaching

water with excess nutrients that can contaminate drinking water or result in algae bloom

flood irrigation

divert water from a main water source to crop area (easy, but requires water nearby and not for all plant types, salinzation)

furrow irrigation

build trenches around where crops are to distribute water between crop rows (low investment, but not efficient on sandy soil and difficult to apply small amounts, salinzation)

spray irrigation

pumps to pump out water and use a nozzle to spray it onto plants (precise application, but expensive and nozzles can clog)

drip irrigation

micro pipes buried under the ground that sweat plants when turned on (very low evaporation rates, but very expensive and requires mechanization)

waterlogging

might occur during flood irrigation, air pockets in soil get filled up with water for plant

salinization

process of increasing salt content in soil or water

aquifer

areas of groundwater where you have concentration of water that is recharged by infiltration from rainfall